Herpothallon, Tobler, 1937

Chen, Pengfei, Liu, Linlin, Xie, Congmiao & Zhang, Lulu, 2022, Four new species of Herpothallon (Arthoniaceae, Arthoniales, Arthoniomycetes, Ascomycota) from China, Phytotaxa 536 (1), pp. 83-91 : 90

Key to the species of Herpothallon known from China

1 Pigments in thallus visible from above, prothallus with red pigment, K+ purple; pseudisidia cylindrical or globose........................ ................................................................................................. H. rubrocinctum (Ehrenb.) Aptroot, Lücking & G. Thor (2009: 61)

- No pigments in thallus, pseudisidia and prothallus visible from above (rarely yellow pigments located in hidden hypothallus) ...... ............................................................................................................................................................................................................2

2 Thallus with globose to granular pseudisidia .....................................................................................................................................3

- Thallus with cylindrical pseudisidia...................................................................................................................................................6

3 Thallus K– and perlatolic acid present .......................................................... H. granulare (Sipman) Aptroot & Lücking (2009: 43)

- Thallus K–/K+ yellow to red and perlatolic acid absent ....................................................................................................................4

4 Psoromic acid chemosyndrome.................................................................................. H. weii Y.L. Cheng & H.Y. Wang (2012: 440)

- Different substances ...........................................................................................................................................................................5

5 Gyrophoric present (C+ bright red, K–).................................................................................................................... H. subglobosum

- Norstictic acid present (C– and K+ orange) ............................................................................................................... H. capilliferum

6 Gyrophoric present (C+ bright red)....................................................................................................................................................7

- Gyrophoric absent (C–) ......................................................................................................................................................................8

7 Thallus K+ yellow, pseudisidia smaller (up to 0.2 × 0.1 mm) .............................................................................. H. viridi-isidiatum

- Thallus K–, pseudisidia larger (up to 1.0 × 0.1 mm).................................................................................................. H. philippinum

8 Psoromic acid (P+ golden yellow) present.................................................................................................................... H. echinatum

- Stictic acid present (P+ orange)................................................................................................................................ H. polyisidiatum